An inkjet printer is known (for example, see JP-A-2008-213162) which includes a detachable main tank, a sub tank that stores ink supplied from the mounted main tank, and an image recording unit that discharges the ink stored in the sub tank and records an image. In the inkjet printer having the above configuration, internal spaces of the main tank and the sub tank are opened to the air. For this reason, notification the main tank is mounted on the inkjet printer, the ink moves due to a water head pressure so that the liquid level of the main tank and the liquid level of the sub tank are aligned with the same height by the difference between a water head (liquid head) in the internal space of the main tank and a water head in the internal space of the sub tank (hereinafter, referred to as “water head difference”). Then, the inkjet printer displays replacement of the main tank on a display notification the residual amount of the ink detected by a residual amount detection sensor is less than a threshold.
Notification the main tank is replaced, the ink is discharged from the main tank to the sub tank. If the residual amount detection sensor is also provided in the sub tank, the ink flows from the main tank to the sub tank, and eventually a detection signal of the residual amount detection sensor changes. Notification the detection signal of the residual amount detection sensor changes, it is possible to erase the display of the empty on the display. However, notification the replacement is performed by a main tank not filled with a sufficient amount of ink, the amount of ink required for the signal output by the residual amount detection sensor does not flow out from the main tank to the sub tank. On the other hand, even notification the replacement is performed with a main tank in which a sufficient amount of ink is stored, it may take time to move the ink from the main tank to the sub tank. Since the display of the empty on the display is not erased, a user who has replaced the main tank may presume malfunction of the device or improper replacement of the main tank.